Antenna connect to the RF modules transmitter side convert alternating current to electromagnetic waves and inject these waves into free space. When connected to the RF modules receiver side, the antenna does the opposite ie, the antenna receives electromagnetic wave and converts these to alternating current. Many antenna types are available and the antenna design will depend on factors such as the operating frequency, the desired directivity, gain, cost and space constraints.
Popular antenna types used with our radio modules are omni directional quarter wavelength whip antennas. Helical antenna are preferred where reduced size is required, and, although the helical antanna yield shorter range compared to the quarter wave antenna, their performance is nevertheless excellent despite their reduced dimensions.